# Unit Testing Implementation

| Field     | Value                                             |
|-----------|---------------------------------------------------|
| Date      | 2025-04-01                                        |
| Author    | Theater Team                                      |
| Status    | Accepted                                          |
| Priority  | High                                              |

## Overview

This change proposes implementing comprehensive unit tests for key components of the Theater WebAssembly actor system. The implementation will follow the testing strategy outlined in the project documentation while focusing on critical components that currently lack test coverage. This will improve code reliability, facilitate future development, and serve as documentation for component functionality.

## Motivation

The Theater project is a complex WebAssembly actor system with multiple interconnected components. Current test coverage appears to be limited, with only a few modules having dedicated tests. Increasing test coverage will help:

1. Ensure reliability of core components
2. Detect regressions during development
3. Document expected behavior of components
4. Facilitate refactoring and maintenance
5. Support future feature development

## Implementation Plan

### 1. Core Component Tests

#### 1.1 State Chain Tests (`src/chain/mod.rs`)

Create a dedicated test module to verify the integrity and functionality of the StateChain component, which is critical for actor state verification. Tests will include:

- Chain event creation verification
- Chain integrity validation
- Parent-child hash relationship verification
- Chain serialization and persistence testing

#### 1.2 Actor Store Tests (`src/actor_store.rs`)

Implement tests for the ActorStore component to verify state management and event recording:

- State management (get/set)
- Event recording and verification
- Chain event retrieval and access
- Chain integrity verification

#### 1.3 Actor Handle Tests (`src/actor_handle.rs`)

Add tests for the ActorHandle component to verify operation handling with mocked responses:

- Operation sending and response handling
- Timeout behavior
- Error propagation
- State retrieval verification
- Metrics collection

### 2. Actor Runtime Component Tests

#### 2.1 Actor Runtime Initialization Tests (`src/actor_runtime.rs`)

Create tests to verify actor initialization and shutdown phases:

- Actor initialization with various configurations
- Shutdown sequence verification
- Handler instantiation and initialization
- Error handling during actor startup

### 3. Message Handling Tests

#### 3.1 Actor Message Tests (`src/messages.rs`)

Create tests for message serialization, deserialization, and routing:

- Message serialization/deserialization verification
- Theater command serialization verification
- Message routing validation
- Error handling for invalid messages

### 4. Handler Interface Tests (`src/host/handler.rs`)

Test the handler interfaces to verify they correctly interact with actors:

- Handler lifecycle (start/stop)
- Interaction with actor handles
- Shutdown signal propagation
- Export function registration

### 5. Content Store Tests (`src/store/mod.rs`)

Implement tests for the content-addressable storage:

- Content storage and retrieval
- Content reference generation
- Label management
- Content deletion and cleanup

## Tests Structure

The tests will be organized according to the testing strategy document:

```
tests/
├── common/                    
│   ├── mod.rs                
│   ├── mocks.rs              
│   └── helpers.rs            
├── integration/              
│   ├── lifecycle_tests.rs    
│   └── messaging_tests.rs    
└── unit/                     
    ├── chain_tests.rs        
    ├── store_tests.rs        
    └── actor_tests.rs        
```

## Testing Utilities

1. Add a mock WASM component for testing
2. Create test helpers for common operations
3. Implement utility functions for test state management

## CI Integration

Update the CI configuration to run the new tests.

## Benefits

This change will provide the following benefits:

1. **Improved Reliability**: Systematic tests will catch bugs and regressions.
2. **Better Documentation**: Tests will serve as executable documentation of expected component behavior.
3. **Easier Maintenance**: Future changes will be safer with test coverage.
4. **Verification of Core Functionality**: Critical components like the state chain will have verified behavior.

## Timeline

1. Phase 1 (1-2 days): Implement core component tests
2. Phase 2 (2-3 days): Implement actor runtime and communication tests
3. Phase 3 (2-3 days): Implement storage and utility tests

Total estimated time: 5-8 days
